Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
The mapping operation
elmapd
Next ⟩
mapdm0
Metamath Proof Explorer
Ascii
Unicode
Theorem
elmapd
Description:
Deduction form of
elmapg
.
(Contributed by
BJ
, 11-Apr-2020)
Ref
Expression
Hypotheses
elmapd.a
⊢
φ
→
A
∈
V
elmapd.b
⊢
φ
→
B
∈
W
Assertion
elmapd
⊢
φ
→
C
∈
A
B
↔
C
:
B
⟶
A
Proof
Step
Hyp
Ref
Expression
1
elmapd.a
⊢
φ
→
A
∈
V
2
elmapd.b
⊢
φ
→
B
∈
W
3
elmapg
⊢
A
∈
V
∧
B
∈
W
→
C
∈
A
B
↔
C
:
B
⟶
A
4
1
2
3
syl2anc
⊢
φ
→
C
∈
A
B
↔
C
:
B
⟶
A